A motor vehicle typically has at least two so-called passenger doors used by the driver and others to get into and out of the vehicle, a rear or trunk door or lid used to gain access to the trunk or to a rear storage space, and a gas-filler door that covers the recess in which the outer end of the fill tube for the gas tank is located. Each such door typically has its own latch and in a vehicle equipped with a central lock system, each latch in turn has its own actuator of the type described in German patent 2,709,157 issued 7 Sep. 1978 to R. Andres and in U.S. Pat. Nos. 4,669,283 and 4,941,694. The actuators can be electrically powered or fluid powered, that is driven by pressurized hydraulic fluid or compressed air.
The central lock system further has a central controller that is typically operated by the driver's-door latch, itself operated mechanically by a key or remotely via a coded radio-frequency or infrared transmitter. Thus such a lock system is fairly complex and therefore quite expensive. Numerous expensive actuators must all be connected to the common controller, resulting in a complicated arrangement.